Many hormones have feedback actions upon LH and GH production. Most notably is estrogen's and androgen's negative feedback upon LH production and positive feedback of GH secretion. We hypothesize that androgen's effect upon LH and GH production is actually mediated through its conversion to estrogen via endogenous aromatase activity. To test this hypothesis, we will administer testosterone (alone or with an aromatase inhibitor) or estrogen via skin patches, and then evaluate pituitary GH and LH release.